The present invention relates to a new and improved apparatus for the dosed delivery of a liquid to the blood vessel of a living being by using an injection syringe--sometimes briefly referred to as simply a syringe--, in particular to an injection apparatus of this type designed to be equipped with different injection syringes.
In its more particular aspects the injection apparatus of the present development is of the type comprising an injector housing which is provided with a drive arrangement containing a motor-driven spindle mechanism, and a retaining or holder member at the front end of the injector housing exchangeably receiving an injection syringe, the piston member of which is operatively connected to the aforementioned spindle mechanism and is displaceable within a cylinder of the syringe.
A device for the dosed delivery of a liquid is known from German Pat. No. 2,805,513 which substantially comprises an injector housing, a motor-driven spindle mechanism disposed in the injector housing, an injector syringe inserted into a retaining or holder member, and a piston member guided within a cylinder member of the injection syringe, said piston member being connected to a shaft of said spindle mechanism by means of a piston rod. A first scale drum is connected to the spindle shaft and a second scale drum is releasably coupled to the first scale drum, the scale drums being designed to limit the volume setting or adjustment and the advancing movement, respectively. By means of this prior art device a precise control, and thus, an injection corresponding exactly to the volume adjusted by the physician is ensured, which is vital for the life of the patient.